ellipsis()
    overflow hidden
    white-space nowrap
    text-overflow ellipsis
flex_center()
    display flex
    align-items center
    justify-content center
    
// 不换行
no-wrap()
  text-overflow: ellipsis
  overflow: hidden
  white-space: nowrap

// 扩展点击区域
extend-click()
  position: relative
  &:before
    content: ''
    position: absolute
    top: -10px
    left: -10px
    right: -10px
    bottom: -10px